Hot topics: Some shampoo makers creating eco-friendly hard cakes

Lather, rinse, repeat. We all do it - usually with a liquid shampoo. But a handful of manufacturers are getting rid of the plastic bottles and the liquid and offering shampoos in solid bars that look like traditional hand soap. Canadian cosmetic company Lush makes nine formulas of solid shampoos, as well as a solid conditioner. J.R. Liggett’s, in New Hampshire, makes six. And countless artisan soap makers also are capitalizing on growing customer demand for a concentrated product that has all the performance of a regular shampoo but with less packaging and fewer chemicals.

Most solid shampoos weigh between 2 and 4 ounces, cost $4 to $11 per bar and last as long as a 24-ounce bottle of a comparable liquid. While all shampoo bars use natural oils – such as olive, coconut or castor – in their formulations, some, such as J.R. Liggett’s, are more natural than others. J.R. Liggett’s shampoo bars are biodegradable and chemical-free. They use saponified oils rather than lauryl sulfate or DEA _ the main foaming agents in traditional shampoos _ as cleansers and they don’t add chemical fragrances. LUSH bars use lauryl sulfate but none of the chemical preservatives found in liquid shampoos to prevent them from growing mold, bacteria and fungi due to having water as the main ingredient. Water is used in liquid shampoos to dilute other ingredients and make the product easier to spread through the hair.

Solid shampoos work by swiping the bar across wet hair once or twice and lathering up as usual. The natural oils in the shampoos are often enough to negate the need for conditioner with some hair types.

Because shampoo bars can soften and disintegrate in puddles of water like regular bar soaps, LUSH offers a reusable shampoo bar tin for $3.95 that can be used to transport the shampoo in carry-on luggage on airplanes, where liquids that are more than 3.4 ounces are disallowed. J.R. Liggett’s sells an unfinished wood drying rack, or shampoo shelf, for $13.95.

Shampoo bars are sold, for the most part, online and through natural food retailers.